Value-Added Modeling of Teacher Effectiveness: An Exploration of Stability across Models and Contexts

Recent policy interest in tying student learning to teacher evaluation has led to growing use of value-added methods for assessing student learning gains linked to individual teachers. VAM analyses rely on complex assumptions about the roles of schools, multiple teachers, student aptitudes and efforts, homes and families in producing measured student learning gains. This article reports on analyses that examine the stability of high school teacher effectiveness rankings across differing conditions. We find that judgments of teacher effectiveness for a given teacher can vary substantially across statistical models, classes taught,